Methods and systems for preparing and performing an object authentication

ABSTRACT

The present invention relates to the field of tracing and anti-counterfeit protection of physical objects, and particularly to preparing and performing a secure authentication of such objects. Specifically, the invention is directed to a method and a system for preparing a subsequent secured authentication of a physical object or group of physical objects by a recipient thereof, to a method and system for authenticating a physical object or group of physical objects, to a method and system of securely providing a time-variant combination scheme for authenticating a physical object or group of physical objects according to the above methods, and to related computer programs corresponding to said methods. The invention is based on the concept of increasing the security level by increasing the information entropy of the data on which the anti-counterfeit protection is based by means of random data communicated to authenticating entities in an algorithmically hidden way.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. application Ser. No.16/271,109, filed Feb. 8, 2019, which is incorporated by reference. U.S.application Ser. No. 16/271,109 claims priority to European (EP) patentapplication No. 18214512.8, filed Dec. 20, 2018, which is incorporatedherein by reference in its entirety.

FIELD OF THE INVENTION

The present invention relates to the field of tracing andanti-counterfeit protection of physical objects, such as products likefor example pharmaceutical products or other health-related products,and particularly to preparing and performing a secure authentication ofsuch objects. Specifically, the invention is directed to a method and asystem for preparing a subsequent secured authentication of a physicalobject or group of physical objects by a recipient thereof, to a methodand system for authenticating a physical object or group of physicalobjects, to a method and system of securely providing a time-variantcombination scheme for authenticating a physical object or group ofphysical objects according to the above methods, and to related computerprograms corresponding to said methods.

BACKGROUND

In many industries, counterfeiting of products is a substantial problemthat significantly impacts not only the revenues of original productmanufacturers, but may even pose a serious threat to health and evenlife of consumers or operators of counterfeited, i.e. fake products.Such safety relevant product categories include in particular parts forautomobiles and aircraft, components for the construction of buildingsor other infrastructure, food, and even medical devices andpharmaceuticals.

Furthermore, in a broad range of different industries traceability ofgoods and physical objects is a key requirement. This applies inparticular to logistics and supply chain infrastructures and to highlyregulated/structured work flow environments. Examples are industry workplaces being controlled by official regulators such as the FDA (US Food& Drug Administration), and/or being certified e.g. according to GMP(Good manufacturing practice), GLP (Good laboratory practice), GCP (Goodclinical practice), or DIN ISO or similar other standards and rules.Each of these regulated environments requires in particular an audittrail and auditable technologies. A further example is the traceabilityof high value products such as industrial spare parts in order to proofauthenticity and intended use of these parts in secondary markets.

In order to limit counterfeiting and provide supply chain and work flowintegrity, including recognition and authentication of products withinwork flows and supply chains, various industries have developed a numberof different protection measures and identification solutions. Broadlyused protection measures comprise adding a so-called security feature toa product, the feature being rather difficult to fake. For example,holograms, optically variable inks, security threads and embeddedmagnetic particles are known security features which are difficult toreproduce by counterfeiters. While some of these security features are“overt”, i.e. can be easily seen or otherwise recognized by a user ofthe product, other security features are “covert”, i.e. they are hiddenand can only be detected by using specific devices, such as sources ofUV-light, spectrometers, microscopes or magnetic field detectors, oreven more sophisticated forensic equipment. Examples of covert securityfeatures are in particular printings with luminescent ink or ink that isonly visible in the infrared part of the electromagnetic spectrum butnot in its visible part, specific material compositions and magneticpigments.

A specific group of security features, which are in particular used incryptography, is known as “Physical Unclonable Functions” (PUFs). PUFsare sometimes also referred to as “Physically Unclonable Functions” or“Physical Random Functions”. A PUF is a physical entity that is embodiedin a physical structure and is easy to evaluate but hard to predict,even for an attacker with physical access to the PUF. PUFs depend on theuniqueness of their physical microstructure, which typically includes arandom component that is already intrinsically present in the physicalentity or is explicitly introduced into or generated in the physicalentity during its manufacturing and which is substantiallyuncontrollable and unpredictable. Accordingly, even PUFs being producedby the exact same manufacturing process differ at least in their randomcomponent and thus can be distinguished. While in most cases, PUFs arecovert features, this is not a limitation and overt PUFs are alsopossible. PUFs are furthermore ideal for enabling passive (i.e. withoutactive broadcasting) identification of physical objects.

PUFs are known in particular in connection with their implementation inintegrated electronic circuits by way of minimal unavoidable variationsof the produced microstructures on a chip within given process-relatedtolerances, and specifically as being used for deriving cryptographickeys therefrom, e.g. in chips for smartcards or other security relatedchips. An example of an explanation and application of such chip-relatedPUFs is disclosed in the article “Background on Physical UnclonableFunctions (PUFs)”, Virginia Tech, Department of Electrical and ComputerEngineering, 2011, which is available in the Internet at the hyperlink:http://rijndael.ece.vt.edu/puf/background.html.

However, also other types of PUFs are known, such as randomdistributions of fibers in paper used as a substrate for makingbanknotes, wherein the distribution and orientation of fibers can bedetected by specific detectors and used as a security feature of thebanknote. Also, upconverting dyes (UCDs), particularly secret mixturesthereof, may be used as PUFs.

In order to evaluate a PUF, a so-called challenge-responseauthentication scheme is used. The “challenge” is a physical stimulusapplied to the PUF and the “response” is its reaction to the stimulus.The response is dependent on the uncontrollable and unpredictable natureof the physical microstructure and thus can be used to authenticate thePUF, and thus also a physical object of which the PUF forms a part. Aspecific challenge and its corresponding response together form aso-called “challenge-response pair” (CRP).

Anti-counterfeit protection methods and systems based on using PUFs toauthenticate products are described in each of the two European PatentApplications published as EP 3 340 212 A1 and EP 3 340 213 (A1) and inthe further European Patent Application EP 18 170 044.4, the content ofeach of which is incorporated herein in its entirety by way ofreference. Further anti-counterfeit protection methods and systems basedon automatic object recognition and authentication based on suchrecognition are described in the further European Patent Application EP18 170 047.7, the content of which is also incorporated herein in itsentirety by way of reference.

Asymmetric cryptography, which is sometimes also referred to as “publickey cryptography” or “public/private key cryptography”, is a knowntechnology based on a cryptographic system that uses pairs of keys,wherein each pair of keys comprises a public key and a private key. Thepublic keys may be disseminated widely and are usually even publiclyavailable, while the private keys are kept secret and are usually onlyknown to their owner or holder. Asymmetric cryptography enables both (i)authentication, which is when the public key is used to verify that aholder of the paired private key originated a particular information,e.g. a message or stored data containing the information, by digitallysigning it with his private key, and (ii) protection of information,e.g. a message or stored data, by way of encryption, whereby only theowner/holder of the paired private key can decrypt the message encryptedwith the public key by someone else.

Recently, blockchain technology has been developed, wherein a blockchainis a public ledger in the form of a distributed database containing aplurality of data blocks and which maintains a continuously-growing listof data records and is hardened against tampering and revision bycryptographic means. A prominent application of blockchain technology isthe virtual Bitcoin currency used for monetary transactions in theInternet. A further known blockchain platform is provided for example bythe Ethereum project. In essence, a blockchain can be described as adecentralized protocol for logging transactions between parties, whichtransparently captures and stores any modifications to its distributeddatabase and saves them “forever”, i.e. as long as the blockchainexists. Storing information into a blockchain involves digitally signingthe information to be stored in a block of the blockchain. Furthermore,maintaining the blockchain involves a process called “blockchainmining”, wherein so-called “miners” being part of the blockchaininfrastructure, verify and seal each block, such that the informationcontained therein is saved “forever” and the block can no longer bemodified.

A further new ledger technology is known by the name of the “Tangle”,which is blockless and permissionless distributed ledger architecture,which is scalable, lightweight, and provides a consensus in adecentralized peer-to-peer system. A prominent related technology usingthe Tangle as a technical basis is known as “IOTA”, which is atransactional settlement and data integrity layer for the Internet ofThings. However, the term “blockless distributed ledger” is not intendedto be limited specifically to the Tangle technology.

SUMMARY OF THE INVENTION

It is an object of the present invention to provide a further improvedway of effectively authenticating a physical object, such as a product,or a group of such objects.

A solution to this problem is provided by the teaching of the appendedindependent claims. Various preferred embodiments of the presentinvention are provided by the teachings of the dependent claims. Inorder to provide better orientation to the reader several headlines (initalics) have been provided to structure the below overview of thevarious aspects of the overall authentication solution provided by thepresent invention. However, these headlines are in no way intended tolimit the invention disclosed herein. In particular, any definitions ofterms provided herein are applicable throughout this document and arenot limited to an application to a particular section, aspect orembodiment contained herein.

1. Preparing a Subsequent Authentication

A first aspect of the invention is directed to a method of preparing asubsequent secured authentication of a physical object or group ofphysical objects by a recipient thereof. In particular, the method maybe implemented as a computer-implemented method.

The method comprises: (i) receiving or generating predicted context datarepresenting a predicted future location relating to a designated nextrecipient of the physical object or group of physical objects and arelated future time of presence of the physical object or group ofphysical objects at that future location; (ii) receiving or generatingrandom context data indicating a random location and a random time;(iii) combining, according to a first predetermined combination scheme,the predicted context data and the random context data to thereby derivemodified context data representing a modified random location and amodified random time, each resulting from the combining; (iv) encryptingthe modified context data to obtain a secured start data packagerepresenting the modified context data; and (v) storing said securedstart data package (SSDP), or causing it to be stored, to a first datastorage being accessible for providing the secured data package for asubsequent secured authentication of a physical object or group ofphysical objects.

The location may particularly be defined in terms of geocoordinates,e.g. based on respective geolocation data generated by means of asatellite-based radio navigation system, such as those known as GPS,GALILEO or GLONASS.

The term “physical object” or in short “object”, as used herein, refersto any kind of physical object, in particular to any kind of man-madeproduct, such as for example and without limitation a pharmaceuticalproduct or other health-related product, or a natural object, such asfor example and without limitation a vegetable or a piece of a naturalraw material; or a packaging of any one or more of the foregoing. Aphysical object may itself comprise multiple parts, e.g. both aconsumable good and a packaging thereof. The term “group of physicalobjects”, as used herein, refers to a group of objects, which are per seseparate or separable, but which are meant to be distributed together,e.g. in a same physical and/or commercially tied bundle or package, andwhich thus stand in a certain relationship to each other with regards totheir distribution to one or more recipients.

The term “authentication”, as used herein, refers to confirming thetruth of an attribute of a physical object, particularly its kind andits originality, claimed true by an entity. The term “securedauthentication” as used herein, refers to an authentication which issecured by one or more protection measures against unauthorizedinterference with the authentication process or the means used for it.By way of example and without limitation, such securing may involveencrypting and/or digitally signing information on which suchauthentication is based as such protection measures. Specifically, said“secured” start data package may be considered information that issecured by any one or more of such protection measures in order toenable a subsequent secured authentication of a physical object or groupof physical objects based on this secured information.

The term “context data”, as used herein, refers to data representing atleast a specific location and time, which thus together define aspecific context, e.g. of an event. In particular, context data mayrelate to an event defining or defined by the presence of a particularphysical object or group of physical objects at the location and timerepresented by the related context data. The location defined in contextdata may particularly relate to a real physical position, e.g. expressedin geo coordinates, or to a virtual position, such as a particular stepor milestone within a defined work flow or process flow, or both.

The term “combination scheme”, as used herein, refers to a scheme, suchas but not limited to a mathematical operation, according to which twoor more data items or sets of data can be combined. The scheme needs tobe inversible and may particularly be an inversible mathematicalfunction. For example and without limitation, such a mathematicalfunction may be defined in terms of an inversible matrix multiplication.Specifically, the combining may comprise without limitation a mereaggregation, such as juxtaposing the bits of two or more binary datasets.

The terms “storing” data or “causing it to be stored”, as used herein,may particularly include storing the data into a blockchain ordistributed ledger in an indirect manner, i.e. by requesting an actualperformance of such storing from one or more intermediaries, such as aminer from a plurality of miners in the case of a blockchain, which thenactually perform(s) the storing.

Where the term “comprising” or “comprises” is used in the presentdescription and claims, it does not exclude other elements or steps.Where an indefinite or definite article is used when referring to asingular noun e.g. “a” or “an”, “the”, this includes a plural of thatnoun unless something else is specifically stated.

The terms “first”, “second”, “third” and the like in the description andin the claims, are used for distinguishing between similar elements andnot necessarily for describing a sequential or chronological order. Itis to be understood that the terms so used are interchangeable underappropriate circumstances and that the embodiments of the inventiondescribed herein are, unless this is explicitly excluded or technicallyimpossible, capable of operation in other sequences than described orillustrated herein.

The headings provided herein are solely intended to provide additionalstructure to this description of the present invention and thus improveits legibility, but they are not intended to limit it in any way.

The method of the first aspect of the present invention defines one ofseveral aspects of an overall object authentication solution presentedherein. Within the overall solution, it serves to prepare a subsequentsecured authentication of a physical object or group of physical objectsby a recipient thereof, for example by a recipient representing a nodein a supply chain for said physical object or objects. It is a purposeof this method, to provide a data package that is secured by means ofencryption and that makes available, to authorized recipients that areenabled to decrypt the data package, an initial set of information whichis needed for said subsequent authentication process. It is noted, thatthis method of preparing a subsequent secured authentication may be andwill in many cases be performed by a different entity than the actualsubsequent authentication itself. In particular, the encrypted datapackage comprises information that is based, in parts, on random data,which adds a further level of security to the authentication process asa whole, because unlike actual supply-chain related context data, suchas location and time at which a particular physical object is present atthat location, random data may typically not be predicted by anunauthorized third party.

In the following, preferred embodiments of this method are described,which may be arbitrarily combined with each other or with other aspectsof the present invention, unless such combination is explicitly excludedor technically impossible.

(a) Selected Embodiments Relating Particularly to the Creation of theSecure Start Data Package

In some embodiments, encrypting the modified context data comprisesencrypting the modified context data by means of an asymmetricencryption scheme and a related public key pertaining to said designatednext recipient. In contrast to symmetric encryption, where theencryption key has to be kept secret and thus has to be exchanged in asecure manner, using asymmetric encryption allows for using public keysfor the encryption. Unlike keys for symmetric encryption, such publickeys may be exchanged openly without creating security issues.

In some embodiments, encrypting the modified context data furthercomprises digitally signing the modified context data or the securedstart data package resulting from the encrypting. The digital signingmay in particular be performed by means of an asymmetric encryptionscheme and a related private key pertaining to a provider of saidphysical object or group of physical objects or to the signing entity.The digital signing may be used to further increase the security of thesubsequent authentication being based on the modified context data, asit adds a further security level allowing for a verification of theoriginality of the encrypted modified context data by a recipient.

The term “digital signature” or “digitally signing” etc., as usedherein, refers to (using) a set of one or more digital values thatconfirms the identity of a sender or originator of digital data and theintegrity of the later. A frequently used way of creating a digitalsignature comprises generating a hash value from the data to beprotected by way of application of a suitable cryptographic hashfunction. This hash value is then encrypted with a private key(sometimes also called “secure key”) of an asymmetric cryptographicsystem, e.g. based on the RSA cryptographic system, wherein the privatekey is typically known only to the sender/originator. Usually, thedigital signature comprises the digital data itself as well as the hashvalue derived from it by the sender/originator. A recipient may thenapply the same cryptographic hash function to the received digital data,use the public key corresponding to said private key to decrypt the hashvalue comprised in the digital signature, and compare the decrypted hashvalue from the digital signature with the hash value generated byapplying the cryptographic hash function to the received digital data.If both hash values match, this indicates that the digital informationhas not been modified and thus its integrity has not been compromised.Furthermore, the authenticity of the sender/originator of the digitaldata is confirmed by way of the asymmetric cryptographic system, whichensures that the encryption using the public key only works, if theencrypted information was encrypted with the private key beingmathematically paired to that public key. The representation of thedigital signature may particularly be implemented using an RFIDtransmitter or a single- or multi-dimensional barcode, such as a QR-Codeor a DATAMATRIX-code or simply as a multi-digit number.

The term “cryptographic hash function”, as used herein, refers to aspecial type of hash function, i.e. of a mathematical function oralgorithm that maps data of arbitrary size to a bit string of a fixedsize (a hash value), which is designed to also be a one-way function,i.e. a function that is easy to compute on every input, but hard toinvert given the image of a random input. Preferably, the cryptographichash function is a so-called “collision resistant” hash function, i.e. ahash function that is designed such that it is difficult, particularlynearly impossible in practice, to find two different data sets d1 and d2such that hash(d1)=hash(d2). Prominent examples of such hash functionsare the hash functions of the SHA-family, e.g. the SHA-3 function or thehash functions of the BLAKE family, e.g. the BLAKE2 function. Inparticular, so-called “provably secure cryptographic hash functions” maybe used. These are hash functions for which a certain sufficientsecurity level can be mathematically proven.

In some embodiments, storing said secured start data package to saidfirst data storage involves storing the secured start data package to ablockchain or a blockless distributed ledger. In this way, the startdata package may be saved and stored in such a way, that it issubstantially impossible to tamper with it, e.g. destroy or manipulateit, in an unauthorized way, and in particular without such tamperingattempt becoming apparent. Furthermore, storing the start data packageto a blockchain or blockless distributed ledger allows for easy accessto the start data package from remote, for example by an authorizedrecipient along a supply chain of the related physical object or groupof objects.

(b) Selected Embodiments Relating Particularly to the Creation ofInitialization Data

In some embodiments, in a first variant, the method further comprises:(i) detecting by means of one or more sensors at least onediscriminating characteristic of said physical object or group ofphysical objects, to obtain for each discriminating characteristicrespective identification data representing an identity of said relatedphysical object or group of physical objects; and (ii) applying a secondpredetermined cryptographic hash function to a data set resulting fromcombining, according to a second predetermined combination scheme, theone or more respective identification data obtained from the set of saidat least one discriminating characteristic and the random context datato obtain an original hash value.

In a second variant, the method further comprises: (i) detecting bymeans of one or more sensors at least one discriminating characteristicof said physical object or group of physical objects to obtain for eachdiscriminating characteristic respective identification datarepresenting an identity of said related physical object or group ofphysical objects; (ii) applying, to each of said identification data, arespective first predetermined cryptographic hash function to obtain arespective initial hash value related to the respective discriminatingcharacteristic; (iii) applying a second predetermined cryptographic hashfunction to a data set resulting from combining, according to a secondpredetermined combination scheme, the one or more respective initialhash values obtained from the set of said at least one discriminatingcharacteristic and the random context data to obtain an original hashvalue (Ho). Accordingly, the second variant differs from the firstvariant in that the step (ii) of applying the first predetermined hashfunction is added.

In a third variant, the method further comprises applying a secondpredetermined cryptographic hash function to the random context data toobtain an original hash value. Accordingly, the third variant differsfrom the first and second variants in that it is not based on detectingany discriminating characteristic of said physical object or group ofphysical objects and deriving the original hash value Ho based thereon.Instead, it relies merely on the random context data as essential input.

For all three of the above variants, the method comprises in additionoutputting initialization data representing said respective originalhash value.

Specifically, the approach according to the second variant is thus basedon a hash stack comprising two subsequent hash operation levels. Thefirst level relates to applying a respective first cryptographic hashfunction to the respective identification data and the second levelrelates to applying a respective second cryptographic hash function tosaid combination of said initial hash values resulting from the firstlevel and said random context data. Using both the initial hash valuesderived from said discriminating characteristic and the contextinformation increases the entropy (in the sense of information theoryand mathematics) of the resulting initialization data. This allows for avery high level of security of the whole authentication process, even incases where the respective individual entropy of said initial hashvalues and/or of the context information is rather limited and woulditself not allow for a sufficient security level. In addition, it alsoallows for limiting the amount of involved data, in particular of datathat has to be exchanged, directly or indirectly, with a recipient, andthus for optimizing efficiency or the authentication process. Withregards to the term “combination scheme”, reference is made to theabove-provided definition thereof.

The first and third variants, on the other hand, have the advantage oflower complexity in comparison to the first advantage and mayparticularly be suitable for applications, where a lower degree ofsecurity than what can be achieved by the first variant is sufficient.

In some related embodiments, the discriminating characteristic isprovided as a particular set of one or more individual discriminatingproperties of said physical object or group of physical objects, bymeans of which it may be safely identified. Such properties mayparticularly comprise properties which are rather difficult to tamperwith, for example because they are specifically secured againsttampering and/or because they are very difficult to tamper with, alreadybased on their nature. European Patent Application EP 18 170 047.7describes such discriminating characteristics and their use for thepurpose of object authentication in detail.

In further related embodiments, the discriminating characteristic isprovided by a specific security feature specifically added to or createdin or on said physical object or group of physical objects. This allowsparticularly for enabling authentication of such physical objects orgroups of physical objects which themselves do not provide reliablediscriminating characteristics of their own, on which a secureauthentication could be based.

In further related embodiments, at least one of said discriminatingcharacteristics comprises a physical unclonable function, PUF.Furthermore, (i) detecting said at least one discriminatingcharacteristic to obtain respective identification data related theretocomprises: (i-1) applying a respective challenge of a respectivepredetermined challenge-response authentication scheme to the PUF totrigger a response by the PUF according to said authentication scheme inreaction to said challenge, and (i-2) detecting said respective responseand generating respective identification data representing saidresponse; (ii) applying a respective first predetermined cryptographichash function comprises applying the respective first predeterminedcryptographic hash function to said data representing said response toobtain a respective PUF-related initial hash value; and (iii) outputtinginitialization data comprises outputting respective identification datarelated to said discriminating characteristic, the identification datacomprising a representation of said respective PUF-related initial hashvalue. In this way, the particular discriminating characteristic ofphysical unclonable functions can be used as a basis of enabling theauthentication of said physical objects or groups of physical objects,which allows for an even greater level of security due to the virtuallyimpossible cloning of PUFs.

In some embodiments, applying said second predetermined cryptographichash function to obtain the original hash value further comprisesapplying same in addition to a time and location-invariant informationidentifying or being otherwise specifically related to the physicalobject or group of physical objects, respectively. Specifically, thephysical object or group of physical objects may be a product or groupof products, respectively, and said time-invariant or location-invariantinformation may comprise a serial number relating to that product orgroup of products. Applying said second predetermined cryptographic hashfunction to said time-invariant or location-invariant information mayparticularly be performed by applying said hash function to a set orother combination of data, wherein such set or other combination of datarepresents, amongst others, said time-invariant or location-invariantinformation. Adding said time and location-invariant information to thedata to which the second predetermined cryptographic hash function isbeing applied adds even further entropy and may thus even increase theachievable security of the overall authentication process. The time andlocation-invariant information, such as for example one or more serialnumbers may particularly be represented by a marking on the physicalobject or group of physical objects and/or may be implemented using anRFID transmitter or a single- or multi-dimensional barcode, such as aQR-Code or a DATAMATRIX-code or simply as a multi-digit number.

In some embodiments, outputting said initialization data comprises oneor more of the following: (i) adding a representation of saidinitialization data to said physical object or group of physicalobjects; (ii) storing said representation of said initialization data orcausing it to be stored to a third data storage and adding to saidphysical object or group of physical objects a representation of apointer indicating where said initialization data can be accessed in thethird data storage. This third data storage may be the same or differentfrom said first data storage mentioned above. Both of these options (i)and (ii) allow for a particularly simple way of communicating saidinitialization data to further recipients along a supply chain for thephysical object or group of physical objects. Specifically, no directcommunication link, such as an electronic data exchange, has to beestablished between a provider and the respective recipient of saidobjects or group of objects.

(c) Selected Embodiments Relating Particularly to Preparing a FurtherSubsequent Authentication by a Further Recipient

In some embodiments, the method further comprises: (i) receiving arequest for determination of a further secured start data packagerelating to further predicted context data representing a furtherpredicted future location relating to a different further designatednext recipient of the physical object or group of physical objects and arelated future time of presence of the physical object or group ofphysical objects at that further future location; and (ii) performingthe present method based on that further predicted context data todetermine and store, or causing it to be stored, said requested furthersecured start data package relating to further predicted context data.This approach enables a forwarding of the physical objects or group ofphysical objects along a supply chain in such a way that such furtherdesignated next recipient may request a respective previous node alongthe supply chain that is adapted to perform the method according tothese embodiments to generate a respective secured start data packagefor a next hop along the supply chain starting at that furtherdesignated next recipient. Accordingly, not every node along the supplychain has to be able to prepare the authentication at a yet furtherrecipient, but instead such previous node, which may particularly playthe role of a central or overall authority to manage the determinationand storage of further secured start data packages, may be requested toperform that preparation instead and provide a respective secured startdata package for said next hop. Specifically, the requested furtherstart data package may be determined based, in addition to therespective predicted context data, on newly generated random contextdata or on random context data previously determined in the course ofdetermining a respective start data package for a previous recipient.

In some related embodiments, the method further comprises storing theresulting further start data package or causing it to be stored in adata storage that is accessible by the further designated nextrecipient. Specifically, without limitation, said data storage may besaid first data storage mentioned above. Storing the resulting furtherstart data package in said data storage provides an efficient way ofmaking it available to said requesting next recipient in a way, where nodirect communication link between the node providing start data packageand the requesting next recipient is needed. Particularly, the datastorage may again be a blockchain or a blockless distributed ledger,which provides a very high level of security against tampering with thatfurther start data package by unauthorized third parties.

(d) Embodiments Relating Particularly to Digitally Signing the OriginalHash Value

In some embodiments, the method further comprises: (i) signing saidobtained original hash value with a digital signature pertaining to asupplier of said physical object or group of physical objects to therespective next recipient; and (ii) including said digital signature inthe output respective initialization data or further initializationdata, respectively. The supplier may particularly be an originalsupplier or an intermediate supplier along the supply chain for saidphysical object or group of physical objects. Accordingly, therespective initialization data refers to original initialization data inthe case of an original supplier and to respective furtherinitialization data in the case of an intermediate supplier. Adding adigital signature further increases the security level, because itprovides a secure possibility of verifying, by the respective recipient,the authenticity of the signed original hash value in the outputinitialization data.

(e) System for Preparing a Subsequent Secured Authentication

A second aspect of the present invention relates to a system forpreparing a subsequent secured authentication of a physical object orgroup of according to the first aspect of the present invention any oneof the preceding claims. Specifically, the system may be adapted toperform this method according to any one or more of its embodimentsdescribed herein. Accordingly, the description of this method and itsembodiments and its advantages applies mutatis mutandis to this system.

2. Method of Authenticating a Physical Object or Group of PhysicalObjects

A third aspect of the present invention relates to a method ofauthenticating a physical object or group of physical objects. Inparticular, the method comprises different alternative variants and maybe implemented as a computer-implemented method.

The method comprises:

(i) receiving and decrypting a secured start data package representingencrypted context data representing a location and a related time torecover said context data;

(ii) receiving or determining current context data representing acurrent location of the physical object or group of physical objects anda related current time of presence of the physical object or group ofphysical objects at that current location;

(iii) combining, according to a predetermined combination scheme, thecurrent context data with the decrypted context data to therebydetermine test context data, wherein the combination scheme defines aninverse operation to a corresponding combination operation previouslyused to generate the received context data;(iv) accessing initialization data related to said physical object orgroup of physical objects to recover from it an original hash valuebeing represented by the initialization data.

The method further comprises, according to said different variants, (v)one of the following processes a) to c):

-   -   a) Detecting, by means of one or more sensors, at least one        discriminating characteristic of said physical object or group        of physical objects to obtain respective identification data        related to said respective discriminating characteristic, this        identification data representing a presumed identity of said        related physical object or group of physical objects; and        -   generating a test hash value by application of a second            predetermined cryptographic hash function to a combination,            according to a further predetermined combination scheme, of            the test context data and each of said identification data            and preferably a time-invariant and location-invariant            information identifying or being otherwise specifically            related to the said physical object or group of physical            objects; or    -   b) Detecting, by means of one or more sensors, at least one        discriminating characteristic of said physical object or group        of physical objects to obtain respective identification data        related to said respective discriminating characteristic, this        identification data representing a presumed identity of said        related physical object or group of physical objects;        -   applying a respective first predetermined cryptographic hash            function to the respective identification data to obtain a            respective initial hash value related to said discriminating            characteristic; and        -   generating a test hash value by application of a second            predetermined cryptographic hash function to a combination,            according to a further predetermined combination scheme, of            the test context data and each of said initial hash values,            and preferably a time-invariant and location-invariant            information identifying or being otherwise specifically            related to the said physical object or group of physical            objects;    -   c) generating a test hash value by application of a second        predetermined cryptographic hash function to the test context        data or to a combination, according to a further predetermined        combination scheme, of the test context data and a        time-invariant and location-invariant information identifying or        being otherwise specifically related to the said physical object        or group of physical objects.

For each of the above processes a) to c), the second predeterminedcryptographic hash function is equal to a corresponding cryptographichash function previously used to determine the original hash valuerepresented by the initialization data, and wherein said furthercombination scheme is equal to a corresponding combination schemepreviously used to determine the original hash value represented by theinitialization data.

The method further comprises: (vi) generating a first reading resultcomprising (vi-1) a representation of the test hash value and arepresentation of the original hash value, or (vi-2) a matching outputindicating whether or not, according to at least one predeterminedmatching criterion, the test hash value matches said original hash valueand thus indicates authenticity of the physical object or group ofphysical objects.

In case any one or more of the above steps of the method fail for anyreason, e.g. if the initialization data cannot be successfully accessedor the secured start data package cannot be read, the first readingresult may particularly comprise or consist of an output indicating anauthentication failure.

This method of authenticating (authentication method) relates to themethod of the first aspect of the present invention (preparation method)in that the latter serves to prepare a subsequent authentication of aphysical object or group of physical objects according to thisauthenticating method according to the third aspect of the presentinvention. Furthermore, this method of authenticating is based on theconcept that the authentication may be performed by comparing two hashvalues, one of which was previously generated by another entity by meansof said method of preparing a subsequent authentication according to thefirst aspect, and the other of which is produced by the respectiveauthenticating recipient itself based on both the related secure startdata package provided as a result of said preparation method andidentification data being derived from the physical object or group ofobjects to be authenticated.

Accordingly, the start data package provides information relating to thepredicted context data of the recipient, i.e. in particular the locationand time, where and when the recipient is meant to receive said physicalobject or group of physical objects, and the authentication method thenuses this start data package, the received original hash value generatedby preparation method, its current context data, and for processvariants a) and b), in addition identification data (or correspondinginitial hash values) derived from a detection of the one or morediscriminating characteristics of the physical object or group ofphysical objects to generate a test hash value. If the physical objector group of physical objects is original and is received at therecipient at the predicted location and time (at least within somedefined tolerance margin which may particularly correspond to theprecision of the determination of the predicted context data and currentcontext data) the test hash value will be a successful reconstruction ofthe original hash value generated by the preparation method andaccordingly the second and test hash values derived by theauthentication method will match, thus indicating a successfulauthentication. Otherwise, the authentication fails. The process ofcomparing the original and test hash values may be performedautomatically or manually on the basis of the output values of these twohash values.

(a) Selected Embodiments Relating Particularly to Obtaining theIdentification Data

In some embodiments, at least one of said discriminating characteristicscomprises a physical unclonable function, PUF, and detecting saiddiscriminating characteristic to obtain respective identification datarelated thereto comprises: (i) applying a respective challenge of arespective predetermined challenge-response authentication scheme to thePUF to trigger a response according to said authentication scheme inreaction to said challenge; and (ii) detecting a respective response bythe PUF in accordance with the respective challenge-responseauthentication scheme in reaction to the challenge and derivingtherefrom said respective identification data. As PUFs are per sevirtually impossible to clone or otherwise reconstruct, their usefurther increases the achievable security level of the overallauthentication solution.

In some embodiments, obtaining the identification data comprises: (i)sensor-based detecting of one or more discriminating characteristics ofsaid physical object or group of physical objects; (ii) generatingobject data representing said one or more discriminating characteristicsof said physical object or group of physical objects; (iii)communicating said object data to a system for automatic objectrecognition; and (iv) receiving the digitally signed identification datafrom said system in response to said communicating of said object data.These embodiments relate particularly to an authentication method, suchas those described in EP 18 170 047.7, where particularly one or morecharacteristics of a physical object or group of physical objects to beauthenticated, which characteristics form part of the objects or groupof objects per se and do not need to be added as a separate securityfeature, form the basis of identifying and thus authenticating theobject or group of objects. In this case, said system for automaticobject recognition is typically different from the recipient itself andis adapted to receive the object data and in return provide an objectrecognition result in the form of digitally signed identification data.

In some embodiments, said physical object or group of physical objectscomprises a marking. The marking comprises a representation of saidinitialization data and/or a representation of a pointer indicating alocation where said initialization data can be accessed; and accessingsaid initialization data comprises, as applicable: (i) reading therepresentation of said initialization data in the marking, or (ii)reading the representation of the pointer in the marking and acquiringthe initialization data from a data storage location indicated by thepointer; and if the initialization data comprises a digital signature,verifying the respective supplier of said physical object or group ofphysical objects based on a verification of said digital signature.Accordingly, these embodiments are particularly useful when the markingserves to communicate the initialization data, directly or indirectlyvia the pointer, to a recipient as an input to the authenticationmethod. In this way, the initialization data is conveyed by the objector group of objects itself, so that no further communication channelfrom the respective supplier to the respective next recipient needs tobe established.

(b) Selected Embodiments Relating Particularly to Outputting and StoringData Relating to the Authentication

In some embodiments, the method further comprises outputting arepresentation of said current context data or a subset thereof orinformation derived therefrom, as a second reading result. Accordingly,the second reading result may particularly represent data related tosupply-chain management, as it indicates context data describing alocation and time, at which the object or group of objects is or waspresent at the current recipient defining a node along the supply chain.Thus, the authentication method serves at the same time as source ofsupply chain management data.

In some embodiments, the method further comprises a storage processcomprising storing the first reading result, or causing it to be stored,into a block of a blockchain of a first set of one or more blockchainsor into one or more nodes of a blockless distributed ledger of a firstset of one or more blockless distributed ledgers. In particular, causingthe first reading result to be stored may comprise causing anotherdevice, such as a separate and optionally even remotely located computerbeing configured to perform (i) blockchain mining or (ii) writing into anode of a blockless distributed ledger, respectively, to store the firstreading result accordingly. These embodiments enable a secure, reliablestorage with very high data integrity, such that it is essentiallyimpossible to manipulate or erase or otherwise taper with or lose suchdata, e.g. due to unintended or deliberate deletion or due to datacorruption. Thus, the complete authentication history remains available.Furthermore, the stored information can be accessed wherever access tothe blockchain respectively distributed ledger is available. This allowsfor a safe and distributed storage and access to the stored data, e.g.for integrity verification purposes such as checking whether a supplierof a product (object) was in fact the originator of the product, or not.Based on this embodiment, the physical world, to which the objectsbelong, can be connected to the power of blockchain or blocklessdistributed ledger technology. Thus, a high degree of traceability ofthe origin and supply chain of physical objects, such as products, canbe achieved.

In some related embodiments, (i) detecting of discriminatingcharacteristics of the physical object or group of physical objectscomprises detecting a plurality of different ones of such discriminatingcharacteristics to obtain based thereon for each of the discriminatingcharacteristics respective individual set of identification datarepresenting the physical object or group of physical objects; (ii)generating the test hash value is performed for each of the individualsets of identification data separately such as to obtain for each of theindividual sets of identification data a respective individual test hashvalue; (iii) generating the first reading result is performed for eachof the individual test hash values separately such as to obtain for eachof the discriminating characteristics a respective individual firstreading result; and (iv) the storage process comprises storing each ofsaid individual first reading results respectively causing to it bestored into a block of a respective individual dedicated blockchain insaid first set of blockchains or into one or more nodes of a respectiveindividual dedicated blockless distributed ledger in said first set ofblockless distributed ledgers. In this way, the achievable security canbe further increased, because on the one hand further discriminatingcharacteristics of the physical object or group of physical objects areinvolved, which such increases the difficulty of counterfeiting same,and on the other hand the individual first reading results are stored indifferent individual dedicated blockchains, which increases thedifficulty of manipulating or otherwise compromising in an unauthorizedway the related data track stored in the blockchain environment orrespective blockless distributive ledger environment. In some variants,these embodiments may be implemented in addition to any one of theabove-described processes a) and b).

In some further related embodiments, the storage process furthercomprises storing said second reading result or causing it to be stored,respectively, into a block of a blockchain of a second set of one ormore blockchains, the blockchain being separate from the blockchains inthe first set of blockchains, or into one or more nodes of a blocklessdistributed ledger of a second set of one or more blockless distributedledgers, the blockless distributed ledger being separate from theblockless distributed ledgers in the first set of blockless distributedledgers, respectively. These embodiments allow for additionally storingand thus saving the second reading result independently from the firstreading result, into a respective other blockchain, thus providing theadvantages discussed in connection with the immediately precedingembodiment also in relation to the second reading result. Usingdifferent blockchains or blockless distributed ledgers for the first andsecond reading results further provides the advantage of easilysupporting a combination of an existing (second) blockchain or blocklessdistributed ledger, respectively, for the second reading result with anadditional first blockchain or blockless distributed ledger,respectively, for the first reading result. Accordingly, differentaccess rights can be easily enabled and the management of theblockchains can be in the hands of different authorities. In particular,these embodiments may be used to verify both whether a supplier of aproduct was in fact its originator, and whether the supply chain was asexpected, or not. In addition, this can be utilized to further increasethe achievable security, because the context information can be used toretroactively identify locations or persons being involved in supplychain, where a potential fraud might have happened as well as potentialrelated dates or time frames.

In some further related embodiments, where the storage process relatesto blockchains:

(i) storing a respective individual first reading result into a block ofa respective blockchain in the first set of blockchains furthercomprises storing a cross-blockchain pointer which logically maps saidblock of said blockchain in the first set of blockchains to acorresponding block of a respective blockchain in the second set ofblockchains, into said block of said blockchain in the first set ofblockchains; and(ii) storing said second reading result in a block of the blockchain inthe second set of blockchains further comprises storing across-blockchain pointer, which logically maps said block of saidblockchain in the second set of blockchains to a corresponding block ofa respective blockchain in the first set of blockchains, into said blockof said blockchain in the second set of blockchains.

Similarly, in some further related embodiments, where the storageprocess relates to blockless distributed ledgers:

(i) storing a respective individual first reading result into a node ofa respective blockless distributed ledger in the first set of blocklessdistributed ledgers comprises storing a cross-ledger pointer whichlogically maps the node of said blockless distributed ledger in thefirst set of blockless distributed ledgers to a corresponding node ofthe respective blockless distributed ledger in the second set ofblockless distributed ledgers, into the node of said blocklessdistributed ledger in the first set of blockless distributed ledgers;and(ii) storing said second reading result in a node of the respectiveblockless distributed ledger in the second set of blockless distributedledgers further comprises storing a cross-blockchain pointer, whichlogically maps said node of the respective blockless distributed ledgerin the second set of blockless distributed ledgers to a correspondingnode of the respective blockless distributed ledger in the first set ofblockless distributed ledgers, into said block of said blocklessdistributed ledger in the second set of blockless distributed ledgers.

In this way, the blockchains or blockless distributed ledgers of thefirst set of blockchains or blockless distributed ledgers, respectively,can be interconnected by the cross-blockchain pointers or cross-ledgerpointers, respectively, to the second set of blockchains or blocklessdistributed ledgers, respectively, and vice versa. This may be used tofurther increase the achievable security level of the present objectauthentication solution. In particular, this can be used to track downattempts of tampering with or counterfeiting objects at different pointsalong a supply chain. For example, this embodiment allows for trackingdown a location and/or a point in time of such an attempt.

(c) Selected Embodiments Relating Particularly to Determining FurtherInitialization Data for a Yet Subsequent Secured Authentication

In some further related embodiments, the method further comprisesdetermining a further secured start data package, and optionally furtherrelated initialization data for a yet subsequent secured authenticationof said physical object or group of physical objects at a yet furtherrecipient thereof. These embodiments relate to one possible variant ofenabling one or more yet further subsequent secured authentications ofsaid physical object or group of physical objects by further recipientsalong a supply chain. In fact, according to this variant, the processdescribed here for is essentially repeated for each next distributionstep, i.e. hop, along the supply chain, such that for each such hop newdedicated initialization data is generated and used for the nextsubsequent authentication at the next recipient. This has the advantage,that the same processes may be reused for multiple hops along the supplychain.

In some related embodiments, determining said further secured start datapackage (and optionally said further initialization data) comprisesissuing a request for determining such further secured start datapackage (and optionally said further initialization data) for a yetsubsequent secured authentication of said physical object or group ofphysical objects at a yet further recipient thereof to an authorizedprovider of said further secured start data package (and optionally saidfurther initialization data) and receiving, for example via a blockchainor distributed ledger or other storage, said requested further securedstart data package (and optionally said further initialization data) inresponse to the request. This allows, in particular, for centralizingthe determination of further secured start data package (and optionallysaid further initialization data) for multiple hops along a supply chainat a single entity, thus providing a particularly high efficiency. Thecentral authorized provider may particularly coincide with the entityperforming the initial, i.e. first, determination of respective firstfurther secured start data package (and optionally said furtherinitialization data) at the beginning of a supply chain, e.g. theoriginal manufacturer or distributor of the physical object or objectssupplied and authenticated along the supply chain.

In some alternative embodiments, determining said further secured startdata package comprises performing the method of the first aspect, suchthat the predicted context data represents a predicted future locationof a further designated next recipient of the physical object or groupof physical objects and a related future time of presence of thephysical object or group of physical objects at that future location.According to these embodiments, each respective current recipient of thephysical object or group of objects determines itself the secured startdata package for the respective next recipient, i.e. for the respectivenext hop, along the supply chain. This has the advantage, that nocentral authorized entity needs to take care of determining all of thesecured start data package for the respective multiple hops along thesupply chain and, accordingly, no respective communication links betweenthe recipients and such central authority need to be present.

In some related embodiments, the method further comprises, by performingthe method of the first aspect according to related embodiments relatingto the determination of initialization data, determining furtherinitialization data based on the same random context data as saidfurther secured start data package and storing or causing said furtherinitialization data to be stored. Therein, the predicted context datarepresents a predicted future location of a further designated nextrecipient of the physical object or group of physical objects and arelated future time of presence of the physical object or group ofphysical objects at that future location. Accordingly, according tothese embodiments, instead of reusing the previously existing securestart data package, a new secure start data package generated is usedfor at least the next subsequent authentication. Optionally, even a new(i.e. further) initialization data is determined, e.g. based on newrandom context data. These various measures may further increase, aloneor in combination, the achievable security level, because the entropy ofthe overall authentication process is further increased.

(d) Object Authentication System

A fourth aspect of the present invention relates to an objectauthentication system being adapted to perform the method of the thirdaspect, preferably according to any one or more of its embodimentsdescribed herein.

In some embodiments the object authentication system is further adaptedto perform the method of the first aspect.

(e) Computer Program

A fifth aspect of the present invention relates to a computer programcomprising instructions, which when executed on one or more processorsof an object authentication system, such as that according to the fourthaspect, causes it to perform the authentication method according to thethird aspect of the present invention.

3. Method and System for Securely Providing a Time-Variant CombinationScheme

A sixth aspect of the present invention relates to a method of securelyproviding a time-variant combination scheme for authenticating aphysical object or group of physical objects according to theauthentication method of the third aspect, comprising: (i) Receiving andstoring data representing the predetermined combination scheme, a timeand location-invariant information identifying or being otherwisespecifically related to the said physical object or group of physicalobjects, and metadata defining a limited validity period of thecombination scheme CS; (ii) Receiving a request for the combinationscheme and identity information identifying or being otherwisespecifically related to a physical object or group of physical objectsfrom a requesting system; (iii) Authenticating the requesting system,e.g. by way of a two-factor authentication scheme; and (iv-1) If therequesting system is successfully authenticated as being authorized andaccording to previously stored metadata corresponding to the receivedidentity information, the related combination scheme to which themetadata pertains is still valid, outputting data representing thatrelated combination scheme over a data channel being secured againstinterception to the requesting system; and (iv-1) otherwise, denying therequest.

In this way one or more of the combination schemes being used in themethods and systems of the other aspects of the present invention may besecurely provided to the relevant nodes (requesting systems) along thesupply chain, which have a need to authenticate the physical objects orgroups of physical objects. In particular, this allows for using one ormore time-variant combination schemes with limited validity periods forsuch authentications, which may be used to further increase theachievable security level of the overall authentication solution.

Further aspects relate to a system and a computer program, respectively,for performing the method of the sixth aspect.

Each of the computer programs described herein may in particular beimplemented in the form of a data carrier on which one or more programsfor performing the method are stored. Preferably, this is a datacarrier, such as a CD, a DVD or a flash memory module. This may be ofadvantage, if the computer program product is meant to be distributed asan individual product independent from the processor platform on whichthe one or more programs are to be executed. In another implementation,the computer program product is provided as a file on a data processingunit, in particular on a server, and can be downloaded via a dataconnection, e.g. the Internet or a dedicated data connection, such as aproprietary or local area network.

BRIEF DESCRIPTION OF THE DRAWINGS

Further advantages, features and applications of the present inventionare provided in the following detailed description and the appendedfigures, wherein:

FIG. 1 schematically illustrates an exemplary system overview of anoverall security solution comprising respective preferred embodiments ofvarious aspects of the present invention;

FIGS. 2A and 2B show a flowchart illustrating a preferred embodiment ofa first phase of a method of preparing a subsequent securedauthentication of a physical object or group of physical objects by arecipient thereof according to the present invention;

FIGS. 3A and 3B show a flowchart illustrating a preferred firstembodiment of the second phase of the method of preparing a subsequentsecured authentication according to the present invention;

FIGS. 4A and 4B show a flowchart illustrating a preferred secondembodiment of the second phase of the method of preparing a subsequentsecured authentication according to the present invention;

FIGS. 5A and 5B show a flowchart illustrating a preferred firstembodiment of a method of authenticating a physical object or group ofphysical objects according to the present invention, which is configuredto be used in connection with the method of FIGS. 2 and 3;

FIGS. 6A and 6B show a flowchart illustrating a preferred secondembodiment of a method of authenticating a physical object or group ofphysical objects according to the present invention which is configuredto be used in connection with the method of FIGS. 2 and 4;

FIG. 7 shows a flowchart illustrating a preferred embodiment of a methodof using one or more a time-variant combination schemes in connectionwith the methods of FIGS. 3A/3B to 6A/6B; and

FIGS. 8A and 8B illustrate various different options of enabling furthersupply steps (hops) along a supply chain using blockchains as datastorages in connection with one or more of the methods described abovewith respect to FIGS. 2 to 7.

In the figures, dashed lines and contours are used to illustratefurther, optional, variants of the respective systems and methods.Furthermore, same reference signs in different figures relate to thesame or corresponding features. It is to be understood, that the figuresmerely describe specific embodiments and that one or more features orsteps described therein may be in fact optional, even if not marked bydashed lines or being explicitly described as “optional”.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

FIG. 1 schematically illustrates an exemplary system overview of anoverall security solution 10 relating to a supply chain having nodes A,B and C and optionally further node B′. For example, A may relate to anoriginal product manufacturer supplying a physical object PO or group ofphysical objects POs, hereinafter collectively referred to as PO(s), isa product or group of products, respectively. In principle, this may beany sort of product(s), and particularly these products may bepharmaceuticals or medical devices. Accordingly, the present inventionis substantially independent from the sort of physical objects to whichit is applied. Node B may be a logistics site, such as a warehouse, ofan intermediate wholesaler, and C may be a point of sales, e.g. a shop,where the PO(s) distributed along the supply chain are eventually soldto end customers. The further node B′ may commercially belong to B andmay for example be an alternative warehouse being located remote from B,such that B may choose to have the PO(s) delivered by A either towarehouse B or to warehouse B′.

At the beginning of the supply process, supplier A uses a preparationsystem 20, which may particularly comprise a computer and means to issuea challenge to a PUF pertaining to the PO(s) and one or more sensors todetect a response generated by the PUF in reaction to the challenge.Alternatively or in addition, preparation system 20 may comprise acamera system configured to create one or more images of the PO(s) andto send them to an object recognition system that is configured torecognized the PO(s) based on said one or more images and to return arespective recognition result comprising at least one discriminatingcharacteristic of said PO(s) to preparation system 20, for example asdescribed in detail in the European Patent Application EP 18 170 044.4.

The preparation system 20 is configured to perform the methodillustrated in FIG. 2 in combination with FIG. 3 or FIG. 4. As will bedescribed in detail below with reference to these figures, preparationsystem 20 generates, while performing these methods, a secure start datapackage SSDP and stores it or causes it to be stored into a first datastorage DS1. Optionally, preparation system 20 also generates andencrypts and preferably also digitally signs random context data RCD andstores it or causes it to be stored in a second data storage DS2. Inaddition, preparation system 20 generates initialization data IND andstores it into a third data storage DS3. The three data storages DS1,DS2 and DS3 may be separate data storages or two of them or even allthree may be the same. Specifically, each of the data storages may beimplemented for example and without limitation as a blockchain or blockless distributed ledger or as a storage in a public-key infrastructurePKI. Specifically, the various data entries stored in the data storagesmay be cross-linked by one of more cross-pointers CP, e.g. in the caseof blockchains, by cross-blockchain pointers each connecting twocorresponding blocks of a specific pair of blockchains.

Each of the further nodes B, B′ and C comprises a respectiveauthentication system 30 a, 30 b and 30 c, respectively. Each of theseauthentication systems 30 a, 30 b and 30 c is configured to perform theauthentication method of FIG. 5 and/or FIG. 6. As will be described indetail below with reference to these figures, a respective system 30 a,30 b or 30 c performing authentication of received PO(s) reads thesecure start data package from the first data storage DS1 andinitialization data IND from the third data storage DS3. Then, theauthentication is performed based on these reading results.

FIG. 2A shows a flowchart illustrating a preferred embodiment of a firstphase 100 of a method of preparing a subsequent secured authenticationof a physical object or group of physical objects by a recipient thereofaccording to the present invention. In particular, the case of supplychain, this method is preferably performed at the beginning of thesupply chain by the first node thereof. In the present example of FIG.1, this is node A, respectively its preparation system 20 andaccordingly, the below description is based on this non-limitingexample. FIG. 2B shows a compact form of the same method of FIG. 2A, butin the more compact form of a data flow chart.

In a step 110, the preparation system 20 receives from another entity,such as a central logistic center, or generates itself predicted contextdata PCD relating to the next node along the supply chain, i.e. in thepresent example, node B. The predicted complex data PCD represents thelocation x_(B) of node B, or more specifically of its system 30 a, and apredicted time t_(B), at which the PO(s) are expected to arrive at B.The predicted context data PCD may particularly be derived fromlogistics planning data, such as a delivery schedule, for the supplychain. The precision of the predicted context data (e.g. in terms ofgeocoordinate range, and units of time, e.g. hours or days or weeks) ispreferably adapted to match the precision with which a future locationand corresponding point in time at which the authentication of the PO(s)at the next node of the supply chain, i.e. in the present example, nodeB, is to happen, can be reliably predicted. For example, if according tocurrent logistics planning data, the PO(s) are scheduled to arrive atnode B on a particular date, and node B relates to industrial premiseshaving a spatial extension of roughly 500 m×500 m, the PCD may bedefined with a time-wise precision of a day (24 h) and the location-wiseprecision of ±500 m.

In a further step 120, preparation system 20 receives from anotherentity, such as said central logistics center or an external computer,or generates itself random context data RCD representing a randomlocation x_(r) and a random time t_(r).

Then, in a step 130, the PCD and the RCD are combined according to afirst predetermined combination scheme CS1 to thereby derive modifiedcontext data MCD representing a modified random location x_(m) and amodified random time t_(m). The first predetermined combination schemeCS1 may be a time-invariant scheme that needs to be set and madeavailable to each of the nodes of the supply chain, where the PO(s) areto be authenticated, only once. Alternatively, CS1 may be time-variant,which further increases the entropy of the security solution and thusthe achievable security level. An example of using a time-variantcombination scheme CS1 according to embodiments of the present inventionwill be provided below in connection with the discussion of FIG. 7.

Each of the RCD and the PCD may optionally represent further informationin addition, although this is not required for the present method. In afurther step 150, the modified context data MCD is encrypted, forexample by a public key PubB of the next recipient B, to obtain asecured start data package SSDP representing the MCD.

In addition, the MCD may be digitally signed by the sending node, i.e.in the present example node A, with a digital signature pertaining to A.The signature step may be performed either (i) before the encryptionaccording to step 140 (option 1), or (ii) after the encryption in a step160 (option 2), wherein instead of the original MCD the SSDP resultingfrom the encryption of the MCD is digitally signed by A with its privatekey PrivA. Then, in a step 170 that completes the first phase 100,unless an optional further step 180 is applied, the SSDP is stored orcaused to be stored by another entity, such as an external computer, tothe first data storage DS1, as described above with reference to FIG. 1.

Optional step 180 relates to a specific embodiment discussed below indetail with reference to FIG. 8. In this embodiment, the random contextdata is stored in a third data storage DS3 to enable another node in thesupply chain to take over the role of node A at a later time, forexample at a time when A is no longer available for the supply chain,even if that other node has not stored itself the random context dataRCD recovered during a previous authentication process, e.g. accordingto FIG. 5A/5B or FIG. 6A/6B.

FIG. 3A shows a flowchart illustrating a preferred first embodiment 200of the second phase of the method of preparing a subsequent securedauthentication according to the present invention. FIG. 3B shows acorresponding data flow chart. Specifically, this first embodimentrelates to the case, where the PO(s) to be authenticated along thesupply chain have or bear themselves a number n=1, 2, 3, . . . ofspecific discriminating characteristics, which may each be particularlya Physical Unclonable Function PUF, for example according to one or moreof the PUF types described above.

In a step 210 of the second phase 200 of the method, preparation system20 detects the n discriminating characteristics, in the present examplePUFs, of the PO(s) to be authenticated along the supply chain to obtainfor each discriminating characteristic respective identification dataIDD representing an identity of said related PO(s).

Then, in an optional step 220, for each of the discriminatingcharacteristics k □ {1, . . . , n}, a respective first cryptographichash function HF_(1,k) is applied to the obtained IDD_(k) of therespective discriminating characteristic k to obtain a respectiveinitial hash value Hi_(k) related to this particular discriminatingcharacteristic k. The respective first cryptographic hash functionsHF_(1,k) related to different discriminating characteristics or IDDs,respectively, may be either equal or different. It is also possible thatsome of them are equal while others are different, as long as therelationship between a particular discriminating characteristic/IDD anda respective first hash function HF_(1,k) remains known and unchanged.In case optional step 220 is omitted, the obtained IDD_(k) take the roleof the corresponding initial hash value Hi_(k) and thus form themselvesinputs to the subsequent combination step 240, described below.

In a further step 230, preparation system 20 reads from the PO(s), forexample from a respective marking thereon, location-invariant andtime-invariant information relating specifically to the PO(s). Forexample, the information may comprise one or more serial numbers beingassigned to the PO(s). Alternatively, particularly if such informationdoes not exist yet, preparation system 20 may itself generate suchlocation-invariant and time-invariant information and assign it to thePO(s) at question. In the present non-limiting example, thelocation-invariant and time-invariant information shall be one or moreserial numbers assigned to the respective PO(s). Herein, the serialnumbers are collectively referred to as SN.

In a yet further step 240, if n>1, the n initial hash values H₁, . . . ,H_(n) (if step 220 is implemented) or values IDD₁, . . . , IDD_(n) (ifstep 220 is not implemented) are combined with the random context dataRCD and the serial number(s) SN according to a second combination schemeCS2 resulting in a data set H (which may for example be only a singlevalue H) representing the result of this combination operation.Preferably, the combination scheme CS2 is information-conserving and/orideally entropy-conserving. For example, the data set resulting from thecombination according to combination scheme CS2 may take the form of amere data aggregation of the respective input data, i.e. the values tobe combined. The aggregation may particularly be represented by asingle-dimensional or multi-dimensional matrix or other type of array.Like the first combination scheme CS1, also the second combinationscheme CS2 may be a time-invariant scheme that needs to be set and madeavailable to each of the nodes of the supply chain, where the PO(s) areto be authenticated, only once. Alternatively, again like CS1, it may bealso be time-variant, wherein each of the nodes of the supply chain thenneeds to be informed about the respective applicable second combinationscheme CS2, in order to enable the respective authentication of thePO(s) at that node. An example of using time-variant combination schemesCS1 and/or CS2 according to embodiments of the present invention will beprovided below in connection with the discussion of FIG. 7.

Then, in a step 250, a further hash value Ho, which will be referred toherein as “original hash value”, is generated by applying a secondcryptographic hash function to the data set H.

In a further step 260, preparation system 20 digitally signs theoriginal hash value Ho with the private key PrivA of A in order to allowa subsequent verification of the origin of Ho in a subsequentauthentication at a node in the supply chain, i.e. in the presentexample at nodes B, B′ and C.

In a yet further step 270, which may particularly be implementedtogether with step 260 as a single combined step, preparation system 20generates initialization data IND representing the original hash valueHo obtained in step 250 along with the digital signature thereofobtained in step 260.

Phase 200 of the method is concluded by a further step 280, wherein arepresentation of the initialization data IND, e.g. a respectivemarking, is added to said PO(s) and/or said representation of IND isstored or caused to be stored to a third data storage DS3 along withadding to said PO(s) a representation of a pointer indicating where theIND can be accessed in DS3. The storage location for the IND within DS3and therefore also the pointer may, for example, be determined based onthe one or more serial numbers SN of the PO(s).

FIG. 4A shows a flowchart illustrating a preferred second embodiment 300of the second phase of the method of preparing a subsequent securedauthentication according to the present invention. FIG. 4B shows acorresponding data flow chart. Specifically, this second embodimentrelates to the case, where the PO(s) to be authenticated along thesupply chain may not have or bear themselves a specific discriminatingcharacteristic, such as for example a Physical Unclonable Function PUF.

In a step 310, which is equal to step 230 in FIG. 2A/2B, preparationsystem 20 reads from the PO(s) or generates itself location-invariantand time-invariant information relating specifically to the PO(s), forexample one or more serial numbers SN being assigned to the PO(s).

In a yet further step 320, preparation system 20 determines a data set Hof a combination, according to a predetermined combination scheme CS3,of the random context data RCD and a time and location-invariantinformation identifying or being otherwise specifically related to thePO(s). For example, this information may be one or more serial numbersSN of the PO(s). Like CS2, the combination scheme CS3 may be atime-invariant scheme or a time-variant scheme (see FIG. 7).

In a yet further step 330 preparation system 20 generates an originalhash value Ho by applying a cryptographic hash function to the obtaineddata set H.

In a yet further (optional) step 340, preparation system 20 digitallysigns the original hash value Ho with the private key of A in order toallow a subsequent verification of the origin of Ho in a subsequentauthentication at a node in the supply chain, i.e. in the presentexample at nodes B, B′ and C.

In a yet further step 350, which may particularly be implementedtogether with step 340 as a single combined step, preparation system 20generates initialization data IND representing the original hash valueHo obtained in step 320, along with the digital signature thereofobtained in step 330, if implemented.

Phase 300 of the method is concluded by a further step 360, wherein arepresentation of the initialization data IND, e.g. a respectivemarking, is added to said PO(s) and/or said representation of IND isstored or caused to be stored to a third data storage DS3 along withadding to said PO(s) a representation of a pointer indicating where theIND can be accessed in DS3. The storage location for the IND within DS3and therefore also the pointer may, for example, be determined based onthe one or more serial numbers SN of the PO(s).

FIG. 5A shows a flowchart illustrating a preferred first embodiment 400of a method of authenticating a physical object or group of physicalobjects according to the present invention, which is configured to beused in connection with the method of FIGS. 2 and 3. FIG. 5B shows acorresponding data flow chart.

The method 400 is designed to be used in particular by those nodes B,B′, C along the supply chain which are not the starting point A of thedistribution of the PO(s) and which thus have a desire to properlyauthenticate the PO(s) received from the respective immediatelypreceding node in the supply chain. The method will now be explainedexemplarily in relation to PO(s) which bear two or more different PUFsas discriminating characteristics. Of course, similar methods based onother, non-PUF discriminating characteristics or a mix of PUF andnon-PUF discriminating characteristics may be used instead, according tofurther embodiments not illustrated herein.

Method 400 comprises a step 410, wherein the respective authenticationsystem 30 a, 30 b or 30 c, which performs the method, applies to each ofthe PUFs of the PO(s) to be authenticated a respective challenge of arespective predetermined challenge-response authentication scheme AS totrigger a response according to the AS in reaction to the challenge. Forsimplification, the following description in FIGS. 5A,B and 6A,B willfocus on authentication system 30 a at node B, although it needs to beunderstood that the same method 400 may be used by all other nodes alongthe supply chain as well.

In step 415 each of the responses of the various PUFs is detected inaccordance with the respective challenge-response authentication schemeand respective identification data IDD, which represent the response,are being derived therefrom.

In a further (optional) step 420, for each of the PUFs k, a respectivefirst predetermined cryptographic hash function H_(1,k) being equal tothe corresponding first cryptographic hash function that was previouslyused in the method of FIG. 3 during the preparation phase 200 for thesame PUF, is applied to the respective IDD to obtain a respectiveinitial hash value Hi_(k) related to that IDD_(k) of PUF k,respectively. Steps 410 to 420 serve to provide the set of initial hashvalues Hi_(k) as a first input to a subsequent combination step 450which will be described below in detail. If step 420 is not implemented,the respect first input to combination step 450 will be instead thecorresponding values IDD_(k) derived in step 415.

Further steps 425 to 440 are designed to provide a second input tocombination step 450. In step 425, the considered system 30 a, e.g.reads, from the first data storage DS1 a secured start data package SSDPrepresenting encrypted context data CD which in turn represents alocation x₀ and a related time t₀. The SSDP is decrypted to recover saidcontext data CD.

In addition, in a step 430, current context data CCD representing thecurrent location x and the related current time t of presence of thePO(s) at their current location x is generated by system 30 a orreceived from another entity, such as a logistics database. Preferably,the current context data CCD has a similar precision as the predictedcontext data.

In a further step 435, system 30 a determines an applicable combinationscheme CS3, which defines an inverse operation with correspondingoperation according to the corresponding combination scheme CS1previously used to generate the received context data CD. Thisdetermination may for example be performed as described below withreference to FIG. 7.

Then, in a step 440, the current context data CCD is combined, accordingto the determined combination scheme CS3, with the decrypted contextdata CD to thereby determine test context data TCD. This combinationoperation of step 440 is in effect the inverse operation of theoperation performed per step 140 of FIG. 2. When the PCD and the CCDhave similar precision, and that precision is matched to thecontext-wise reliability of the supply chain logistics, theauthentication becomes more robust against acceptable differencesbetween the locations and/or particularly the points in time indicatedby the PCD and CCD, respectively. Accordingly, if the current contextdata CCD matches the corresponding PCD, at least within said precision,and the SSDP has not been corrupted, the resulting TCD is expected tomatch the original random context data RCD.

Further step 445 is designed to provide a third input to subsequentcombination step 450. In step 445, system 30 a reads from data storageDS3 initialization data IND related to said PO(s) that was previouslystored in DS3 according to step 340 of method phase 300. If the storedinitialization data IND was digitally signed before storing it, readingthe initialization data IND comprises verifying the respective digitalsignature by which the IND was digitally signed and recovering theoriginal hash value Ho represented by the initialization data IND. Ho isthen available as said third input to combination step 450, whichfollows.

In said combination step 450, system 30 a generates a test hash value Htby application of a second predetermined cryptographic hash function toa predetermined combination Hc of the initial hash values Hi_(k), theTCD and one or more serial numbers SN provided on the PO(s). The secondpredetermined cryptographic hash function is equal to the correspondingcryptographic hash function HF2 used to determine Ho, as represented bythe IND, in step 230 of method phase 200.

Finally, method 400 is concluded by step 455, wherein authenticationsystem 30 a generates and outputs a first reading result RR1 indicatingwhether or not, according to at least one predetermined matchingcriterion, HT matches Ho and thus indicates authenticity of the PO(s).

FIG. 6A shows a flowchart illustrating a preferred second embodiment 500of a method of authenticating a physical object or group of physicalobjects according to the present invention, which is configured to beused in connection with the method of FIGS. 2 and 4. FIG. 6B shows acorresponding data flow chart.

The second embodiment 500 differs from the first embodiment 400described above in connection with FIG. 5 in that no discriminatorycharacteristics of the PO(s) are available or being used.

Accordingly, in method 500, there are on the one hand no stepscorresponding to steps 410 to 420 of method 400, while on the other handthere are steps 510 to 530, which correspond to and may particularly beidentical to steps 425 to 445. Further step 535 of method 500 differsfrom corresponding step 450 of method 400 in that now the test hashvalue Ht is generated by application of a respective cryptographic hashfunction HF2 to a predetermined combination Hc of the test context dataTCD and the one or more serial numbers SN provided on the PO(s). Thefinal output step 540 of method 500 is again identical to step 455 ofmethod 400.

While the embodiment of method 400 (and method 200) may be used toachieve higher security levels than those that are available when usingmethod 500 (and method 300), the latter has the advantage of lowercomplexity and may thus be preferable, when in view of a moderatedesired security level keeping the complexity and thus costs and effortsfor implementing the system low has priority.

FIG. 7 shows a flowchart illustrating a preferred embodiment of a method600 of using one or more a time-variant combination schemes inconnection with the methods of FIGS. 3A/3B to 6A/6B. When a recipient,such as node B, needs to authenticate a received PO(s), it will firsthave to recover the applicable time-variant combination schemes CS, suchas for example CS2 and/or CS3.

The solution to this problem according to embodiment of FIG. 7 is basedon a trusted authority TC, such as for example a trust center as it isknown from public key infrastructures (PKI). In another example, theoriginal supplier A may itself be or provide the trust center TC.

During a process of preparing a subsequent authentication, for examplein the process according to the methods 100/200 or 100/300 describedabove with reference to FIG. 2 and FIGS. 3A/3B, or FIG. 2 and FIGS.4A/4B, in a step 605, node A stores or causes to be stored into a datastorage DS, e.g. DS1, of the trust center TC one or more serial numbersSN and pertaining to a particular PO(s) to be distributed andauthenticated along a given supply chain, the relevant combinationscheme CS, such as an inversible mathematical formula or anothersuitable inversible data processing scheme, and metadata MD(CS(SN))related to the combination scheme CS applicable for the PO(s) withserial number(s) SN. The metadata MD(CS(SN)) may particularly compriseinformation defining a limited validity period of the combination schemeCS, such that it is no longer applicable once the validity period hasexpired.

When B receives the PO(s) and needs to authenticate them, it sends in astep 610 a respective request to the trust center TC along with thePO(s)'s serial number(s) SN and predefined identification informationthat allows for a two factor authentication 2FA, i.e. a furtherauthentication of B by the trust center which is independent from theprivate key PrivB of B (that is for example used to decrypt the SSDPduring the authentication process for the PO(s)). The identificationinformation may for example comprise a PIN and a TAN, similar to knownprocedures for online banking, a photo TAN, a password or may be basedon a further independent public/private key pair.

The trust center TC then verifies in a 2FA-step 615 the identificationinformation received from B in order to authenticate B and alsoretrieves in a step 620 the meta data MD(CS (SN)) from the data storageDS. In step 625, the meta data MD(CS (SN)) is checked in order todetermine if requested combination scheme CS is still valid and theresult of the authentication step 615 is evaluated. If thisauthentication of B and/or check fails (625—no), an error message isreturned to B in a step 630. Otherwise (625—yes), the received serialnumber(s) SN is used in a step 635 as an index to query a database inthe data storage DS to retrieve in a step 640 the desired combinationscheme CS(SN) and encrypted in a further step 645, e.g. with the publickey of B. When B receives the encrypted combination scheme CS(SN), itdecrypted in the step 650, e.g. with its private key, in order to obtainthe desired combination scheme CS(SN). While using asymmetric encryptionis a suitable approach for implementing the encryption/decryption ofsteps 645 and 650, any other approach for sufficiently securing thecommunication between TC and B against interception may instead be usedinstead. In FIG. 7, the secured communication between and TC isindicated as a respective secured “tunnel” T which may be separate foreach of the communications or a joint tunnel for two or more of thecommunication links. For example, a symmetric encryption may be used.Also, if asymmetric encryption is used for that purpose, a differentpair of keys may be used than in other steps of the methods describedabove.

In summary, in order for B to successfully authenticate the receivedPO(s), three conditions (factors) need to be fulfilled: (1) B needs toprocess his private key PrivB, (2) the authentication needs to takeplace at the correct location (node B) and timeframe defined by A in thepredicted context data PCD during the preparation phase 200, and (3) Bneeds to have the valid identification information needed to access therelevant one or more time-variant combination schemes CS, e.g. CS2and/or CS3. Accordingly, the authentication of the PO(s) would fail, ifthe PO(s) were originally scheduled to arrive at node B at a given time,as defined in the related predicted context data PCD, but the PO(s) wereactually provided instead to B's other warehouse location (node B′),i.e. at a different time and to a different location (cf. FIG. 1). Thus,when B wants A to redirect the distribution of PO(s) from mode A to nodeB′ (instead of node B), B needs to inform A of this desire and then Aneeds to prepare and store an update start data package SSDP reflectingthis redirection to node B′.

FIGS. 8A and 8B illustrate various different options of enabling furthersupply steps (hops) along a supply chain using blockchains as datastorages in connection with one or more of the methods described abovewith respect to FIGS. 2 to 7. Specifically, FIG. 8A relates toembodiments, where node A is defined as the sole authority along thesupply chain for determining the respective start data package for eachhop. In addition, A may be the sole authority to also define furtherinitialization data IDD replacing the original initialization datarelating to a particular PO(s). While for each hop along the supplychain, a new secured start data package is needed, which is based on therespective predicted context data PCD for the recipient of therespective next hop, the initialization data may either be maintainedunchanged or also changed.

For example, when in the embodiment of FIG. 8A the PO(s) supplied alongthe supply chain from A to C have reached node B and have beensuccessfully authenticated there, B issues a request R to the soleauthority, which is node A, to issue the necessary new SSDP(C) for thehop from B to C. Typically, B will provide predicted context data for Cto A to enable the determination of a correct SSDP(C) either via one ofthe data storages DS1 to DS3 or over a separate, preferably securedinformation channel. Optionally, B may also request, e.g. as part ofrequest R, new initialization data IND(C) based on new random contextdata RCD. As the RCD is needed to determine both the requested SSDP(C)and the IND(C) these two requested data items are related, as they arebased on the same RCD. Per the request, A determines SSDP(C) andoptionally also IND(C) and stores the result in the related data storageDS1 and DS3, respectively. When the PO(s) sent by B arrive at node C,system 30 c of C can read SSDP(C) and, if applicable, IND(C) andsuccessfully authenticate the PO(s) based thereon, provided the currentcontext data (CCD) of C matches the PCD based on which the SSDP(C) wasdetermined by A.

FIG. 8B, the contrary, relates to embodiments, where a former recipientof the PO(s) may itself take over the role of determining the necessarySSDP and optionally also related further IND for the next hop startingat that node. For example, node B may take over the previous role A hadin relation to the hop from A to B for the further hop from B to C. Inany case, B needs to determine the new SSDP(C) for C based on therelated predicted context data for C. The random context data RCD usedfor this determination may either remain the same as for the previoushop. Accordingly, in the first variant, B may use the RCS determined asa result of the previous authentication of the PO(s) at node B uponarrival from node A. In the second variant, however, B needs to generateor receive new random context data and thus also determine the SSDP(C)and new initialization data IND(C) based thereon and store it into DS1and DS3, respectively. The authentication process for the PO(s) at nodeC is then similar to that in the case of FIG. 8A.

Another related variant of the embodiments of FIG. 8B is a case, wherethe new SSDP(C) and optionally new initialization data IND(C) needs tobe determined based on the original random context data RCD originallydetermined by A, but where such RCD is no longer available at A and B ormay be even A or its data is no longer existing at all. This may forexample occur in cases, where the gross travel time of the PO(s) alongthe supply chain is rather long (e.g. years), as may be the case forgoods having typically long storage times between consecutive hops, e.g.in the case of (raw) diamonds. A solution may then be that, asillustrated in FIGS. 1 and 8B, A stores its RCD into a data storage,e.g. DS 2, is a secured manner, e.g. encrypted, such that B or anyauthorized further node B may access it even when the original RCD is nolonger available to B otherwise. B can then access RCD in DS2 andcontinue based thereon the data flow corresponding to the supply chainbased on the method of FIG. 8B and the original RCD.

While above at least one exemplary embodiment of the present inventionhas been described, it has to be noted that a great number of variationsthereto exists. Furthermore, it is appreciated that the describedexemplary embodiments only illustrate non-limiting examples of how thepresent invention can be implemented and that it is not intended tolimit the scope, the application or the configuration of theherein-described apparatus' and methods. Rather, the precedingdescription will provide the person skilled in the art with instructionsfor implementing at least one exemplary embodiment of the invention,wherein it has to be understood that various changes of functionalityand the arrangement of the elements of the exemplary embodiment can bemade, without deviating from the subject-matter defined by the appendedclaims and their legal equivalents.

LIST OF REFERENCE SIGNS

-   10 overall security solution-   20 preparation system of node A-   30 a,b,c authentication systems of nodes B, B′, and C, respectively-   2FA two factor authentication-   A, B, C nodes of supply chain-   CCD current context data-   CP cross-pointer, e.g. cross-blockchain pointer-   CD encrypted context data-   CS combination scheme, e.g. one of CS1, CS2 and CS3-   CS1 first combination scheme-   CS2 second combination scheme-   CS3 third combination scheme, inverse of CS1-   Dec decryption-   DS data storage, in particular one of DS1, DS2 and DS3-   DS1, . . . , DS3 data storages, e.g. blockchains-   Enc encryption-   H data set, e.g. single value-   HF1, HF2 hash functions-   Hc predetermined combination of the initial hash values-   Hi initial hash value-   Ho original hash value-   Ht test hash value-   IDD identification data-   IND initialization data-   k discriminating characteristic or corresponding index thereto,    respectively-   MCD modified context data-   PCD predicted context data-   PIN personal identification number-   PO(s) physical objects or group of physical objects-   PrivA private key of A-   PrivB private key of B-   PubA public key of A-   PubB public key of B-   PUF1-PUFn physical unclonable functions (PUF)-   R request-   RCD random context data-   RR1 first reading result-   Sign create digital signature-   SN serial number(s)-   SSDP secured start data package-   T secured channel, tunnel-   TAN transaction number-   TC system of securely providing a time-variant combination scheme,    trust center-   TCD test context data

The invention claimed is:
 1. A method of preparing a subsequent securedauthentication of a physical object or group of physical objects (PO(s))by a recipient (B, B′) thereof, the method comprising: determininglocation-invariant and time-invariant information relating specificallyto said PO(s) and a random context data (RCD) indicating a randomlocation and a random time; combining, to obtain a data set, accordingto a time-variant first predetermined combination scheme (CS3), saidlocation-invariant and said time-invariant information relating to saidPO(s) with said RCD; generating, an original hash value (Ho) by applyinga cryptographic hash function to said obtained data set; signing said Howith a digital signature; outputting initialization data (IND)representing said Ho including said digital signature; storing orcausing to be stored, said IND to a third data storage (DS3), whereinstoring said IND to said DS3 involves storing said IND to a blockchainor a blockless distributed ledger; and adding to said PO(s) arepresentation of a pointer indicating where said IND can be accessed insaid DS3.
 2. The method of claim 1, further comprising applying a secondpredetermined cryptographic hash function (HF2) to obtain said Ho,wherein applying said HF2 comprises applying a time andlocation-invariant information (SN) identifying or being otherwisespecifically related to said PO(s), respectively.
 3. The method of claim1, further comprising: adding a representation of said IND to saidPO(s).
 4. The method of claim 1, further comprising: signing said Howith a digital signature pertaining to a supplier (A) of said PO(s) tosaid B, B′; and including said digital signature pertaining to said A inthe IND.
 5. A system for preparing a subsequent secured authenticationof a physical object or group of physical objects (PO(s)), the systemcomprising: a processor implemented in hardware; and memory comprisinginstructions that when executed by the processor, cause the processorto: determine location-invariant and time-invariant information relatingspecifically to said PO(s) and a random context data (RCD) indicating arandom location and a random time; combine, to obtain a data set,according to a time-variant first predetermined combination scheme(CS3), said location-invariant and said time-invariant informationrelating to said PO(s) with said RCD; generate, an original hash value(Ho) by applying a cryptographic hash function to said obtained dataset; sign said Ho with a digital signature; output, initialization data(IND) representing said Ho including said digital signature; store orcause to be stored, said IND to a third data storage (DS3); and add tosaid PO(s) a representation of a pointer indicating where said IND canbe accessed in the DS3.
 6. A method of authenticating a physical objector group of physical objects (PO(s)), the method comprising: receivingand decrypting a secured start data package (SSDP) representingencrypted context data (CD) representing a location and a related timeto recover said context data (CD); receiving or determining currentcontext data (CCD) representing a current location of said PO(s) and arelated current time; combining, according to a predeterminedcombination scheme (CS3), said CCD with said decrypted CD to therebydetermine test context data (TCD), wherein said CS3 defines an inverseoperation to a corresponding combination operation (CS1) previously usedto generate said CD; accessing initialization data (IND) related to saidPO(s) to recover an original hash value (Ho) being represented by saidIND; the method further comprising one of the following processes a) toc): a) detecting by means of one or more sensors at least onediscriminating characteristic (k) of said PO(s) to obtain respectiveidentification data (IDDk) related to said k, said IDDk representing apresumed identity of said PO(s); and generating a test hash value (Ht)by application of a second predetermined cryptographic hash function(HF2) to a combination (Hc), according to a further predeterminedcombination scheme (CS2), of the said TCD and each of said IDDk and atime-invariant and location-invariant information (SN) identifying orbeing otherwise specifically related to the said PO(s); or b) detectingby means of one or more sensors at least one said k of said PO(s) toobtain said IDDk related to said k, said IDDk representing a presumedidentity of said PO(s); applying a respective first predeterminedcryptographic hash function (HF1,k) to said IDDk to obtain a respectiveinitial hash value (Hik) related to said k; and generating said Ht byapplication of said HF2 to said Hc, according to said CS2, of said TCDand each of said Hik, and a time-invariant and location-invariantinformation identifying or being otherwise specifically related to thesaid physical object or group of physical objects; or c) generating saidHt by application of said HF2 to said TCD or to said Hc, according tosaid CS2, of said TCD and a time-invariant and location-invariantinformation identifying or being otherwise specifically related to thesaid physical object or group of physical objects; wherein for therespective one of the processes a) to c), said HF2 is equal to acorresponding cryptographic hash function previously used to determinesaid Ho represented by said IND, and wherein said CS2 is equal to acorresponding combination scheme previously used to determine said Horepresented by said IND; and the method further comprises: generating afirst reading result (RR1) comprising: a representation of said Ht and arepresentation of said Ho, or a matching output indicating whether ornot, according to at least one predetermined matching criterion, said Htmatches said Ho and thus indicates authenticity of the physical objector group of physical objects; and storing or causing to be stored saidRR1 into a block of a blockchain of a first set of one or moreblockchains or into one or more nodes of a blockless distributed ledgerof a first set of one or more blockless distributed ledgers.
 7. Themethod of claim 6, wherein said k comprises a physical unclonablefunction (PUF); and detecting said k to obtain respective identificationdata related thereto comprises: applying a respective challenge of arespective predetermined challenge-response authentication scheme to thePUF to trigger a response according to said authentication scheme inreaction to said challenge; and detecting a respective response by thePUF in accordance with the respective challenge-response authenticationscheme in reaction to the challenge and deriving therefrom saidrespective identification data.
 8. The method of claim 6, whereinobtaining said IDDk comprises: sensor-based detecting of said k of saidPO(s); generating object data representing said k of said PO(s);communicating said object data to a system for automatic objectrecognition; and receiving the digitally signed identification data fromsaid system in response to said communicating of said object data. 9.The method of claim 6, wherein: detecting said k of said PO(s) comprisesdetecting a plurality of different said k to obtain based thereon foreach of said k respective to each individual set of said IDDkrepresenting said PO(s); generating said Ht is performed for each of theindividual sets of said IDDk separately such as to obtain for each ofthe individual sets of said IDDk a respective said Ht; generating saidRR1 is performed for each of said Ht separately such as to obtain foreach of said k a respective said RR1; and the storage process comprisesstoring each of said RR1 respectively causing it to be stored into ablock of a respective individual dedicated blockchain in said first setof blockchains or into one or more nodes of a respective individualdedicated blockless distributed ledger in said first set of blocklessdistributed ledgers.
 10. The method of claim 6, further comprisingdetermining a further secured start data package (SSDP) for a subsequentsecured authentication of said PO(s) at a further recipient (C) thereof.11. The method of claim 10 wherein determining said SSDP comprises:issuing a request (R) for determining said SSDP for a subsequent securedauthentication of said PO(s) at said C thereof to an authorized provider(A) of said SSDP and receiving said SSDP in response to the request. 12.The method of claim 11, wherein determining said SSDP comprises:determining a predicted context data (PCD) representing a predictedfuture location of said C of said PO(s) and a related future time ofpresence of said PO(s) at that future location.
 13. The method of claim12, further comprising: determining further said IND based on said RCDas said SSDP and storing or causing said IND to be stored.
 14. An objectauthentication system, comprising: a processor implemented in hardware;and memory comprising instructions that when executed by the processor,cause the processor to: receive and decrypt a secured start data package(SSDP) representing encrypted context data (CD) representing a locationand a related time to recover said context data (CD); receive ordetermine current context data (CCD) representing a current location ofsaid PO(s) and a related current time; combine, according to apredetermined combination scheme (CS3), said CCD with said decrypted CDto thereby determine test context data (TCD), wherein said CS3 definesan inverse operation to a corresponding combination operation (CS1)previously used to generate said CD; access initialization data (IND)related to said PO(s) to recover an original hash value (Ho) beingrepresented by said IND; said memory further comprising instructionsthat when executed by the processor, cause the processor to: a) detectby means of one or more sensors at least one discriminatingcharacteristic (k) of said PO(s) to obtain respective identificationdata (IDDk) related to said k, said IDDk representing a presumedidentity of said PO(s); and generating a test hash value (Ht) byapplication of a second predetermined cryptographic hash function (HF2)to a combination (Hc), according to a further predetermined combinationscheme (CS2), of the said TCD and each of said IDDk and a time-invariantand location-invariant information (SN) identifying or being otherwisespecifically related to the said PO(s); or b) detect by means of one ormore sensors at least one said k of said PO(s) to obtain said IDDkrelated to said k, said IDDk representing a presumed identity of saidPO(s); applying a respective first predetermined cryptographic hashfunction (HF1,k) to said IDDk to obtain a respective initial hash value(Hik) related to said k; and generating said Ht by application of saidHF2 to said Hc, according to said CS2, of said TCD and each of said Hik,and a time-invariant and location-invariant information identifying orbeing otherwise specifically related to the said physical object orgroup of physical objects; or c) generate said Ht by application of saidHF2 to said TCD or to said Hc, according to said CS2, of said TCD and atime-invariant and location-invariant information identifying or beingotherwise specifically related to the said physical object or group ofphysical objects; wherein for the respective one of the processes a) toc), said HF2 is equal to a corresponding cryptographic hash functionpreviously used to determine said Ho represented by said IND, andwherein said CS2 is equal to a corresponding combination schemepreviously used to determine said Ho represented by said IND; and saidmemory further comprising instructions that when executed by theprocessor, cause the processor to: generate a first reading result (RR1)comprising: a representation of said Ht and a representation of said Ho,or a matching output indicating whether or not, according to at leastone predetermined matching criterion, said Ht matches said Ho and thusindicates authenticity of the physical object or group of physicalobjects.
 15. A non-transitory computer readable medium comprisinginstructions, which when executed on one or more processors of an objectauthentication system cause the one or more processors to: receive anddecrypt a secured start data package (SSDP) representing encryptedcontext data (CD) representing a location and a related time to recoversaid context data (CD); receive or determine current context data (CCD)representing a current location of said PO(s) and a related currenttime; combine, according to a predetermined combination scheme (CS3),said CCD with said decrypted CD to thereby determine test context data(TCD), wherein said CS3 defines an inverse operation to a correspondingcombination operation (CS1) previously used to generate said CD; accessinitialization data (IND) related to said PO(s) to recover an originalhash value (Ho) being represented by said IND; said non-transitorycomputer readable medium further comprising instructions that whenexecuted by the processor, cause the processor to: a) detect by means ofone or more sensors at least one discriminating characteristic (k) ofsaid PO(s) to obtain respective identification data (IDDk) related tosaid k, said IDDk representing a presumed identity of said PO(s); andgenerating a test hash value (Ht) by application of a secondpredetermined cryptographic hash function (HF2) to a combination (Hc),according to a further predetermined combination scheme (CS2), of thesaid TCD and each of said IDDk and a time-invariant andlocation-invariant information (SN) identifying or being otherwisespecifically related to the said PO(s); or b) detect by means of one ormore sensors at least one said k of said PO(s) to obtain said IDDkrelated to said k, said IDDk representing a presumed identity of saidPO(s); applying a respective first predetermined cryptographic hashfunction (HF1,k) to said IDDk to obtain a respective initial hash value(Hik) related to said k; and generating said Ht by application of saidHF2 to said Hc, according to said CS2, of said TCD and each of said Hik,and a time-invariant and location-invariant information identifying orbeing otherwise specifically related to the said physical object orgroup of physical objects; or c) generate said Ht by application of saidHF2 to said TCD or to said Hc, according to said CS2, of said TCD and atime-invariant and location-invariant information identifying or beingotherwise specifically related to the said physical object or group ofphysical objects; wherein for the respective one of the processes a) toc), said HF2 is equal to a corresponding cryptographic hash functionpreviously used to determine said Ho represented by said IND, andwherein said CS2 is equal to a corresponding combination schemepreviously used to determine said Ho represented by said IND; and saidnon-transitory computer readable medium further comprising instructionsthat when executed by the processor, cause the processor to: generate afirst reading result (RR1) comprising: a representation of said Ht and arepresentation of said Ho, or a matching output indicating whether ornot, according to at least one predetermined matching criterion, said Htmatches said Ho and thus indicates authenticity of the physical objector group of physical objects.
 16. A method of securely providing atime-variant combination scheme (CS) for authenticating a physicalobject or group of physical objects (PO(s)), the method comprising:receiving and storing data representing said CS, a time andlocation-invariant information (SN) identifying or being otherwisespecifically related to the said PO(s), and metadata (MD) defining alimited validity period of said CS; receiving a request for said CS andsaid SN from a requesting authentication system; authenticating therequesting authentication system; and when the requesting system issuccessfully authenticated as being authorized and according to said MDcorresponding to said CS and said SN to which said MD pertains is stillvalid, outputting data said CS and said SN over a data channel (T) beingsecured against interception to the requesting system and storing saidCS and said SN to a blockchain or a blockless distributed ledger; orotherwise, denying the request.
 17. A system (TC) of securely providinga time-variant combination scheme (CS) for authenticating a physicalobject or group of physical objects (PO(s)), said TC comprising: aprocessor implemented in hardware; and memory comprising instructionsthat when executed by the processor, cause the processor to: receive andstore data representing said CS, a time and location-invariantinformation (SN) identifying or being otherwise specifically related tothe said PO(s), and metadata (MD) defining a limited validity period ofsaid CS; receive a request for said CS and said SN from a requestingauthentication system; authenticate the requesting authenticationsystem; and when the requesting system is successfully authenticated asbeing authorized and according to said MD corresponding to said CS andsaid SN to which said MD pertains is still valid, output data said CSand said SN over a data channel (T) being secured against interceptionto the requesting system and storing said CS and said SN to a blockchainor a blockless distributed ledger; or otherwise, deny the request.